Powder actuated tool

ABSTRACT

A powder actuated tool, including a barrel for receiving in one end thereof a driveable fastener, a driving ram slideable within the barrel for driving the driveable fastener, and a chamber for receiving an explosive cartridge in the end opposite the driveable fastener. Said barrel pivotally mounted to a handpiece whereby in a firing position the cartridge is nested within a breech block provided in the handpiece, and being pivotable away from said breech block for loading and unloading cartridges. Said barrel including a sleeve having a finger adapted to engage and dislodge a cartridge from its chamber, and further including a dog adapted to engage the driving ram for moving the driving ram rearwardly within the barrel. Said dog for moving the driving ram and said finger for retracting the cartridge being cooperative whereby the return of the driving ram creates air pressure behind the cartridge at a point prior to full retraction of the driving ram, and at said point having the finger engaging (and thus dislodging) the cartridge whereby the continued retraction exerts a propelling force to propel the cartridge out of the barrel end.

United States Patent [1 1 Pomeroy 1 1 POWDER ACTUATED TOOL RaymondVisher Pomeroy, Portland, Oreg.

[75] Inventor:

[73] Assignee: Omark Industries, Inc., Portland,

Ohio

[22] Filed: June 2, 1972 [21] Appl. No.: 259,103

Primary ExaminerGranvi1le Y. Custer, Jr.

[57] ABSTRACT A powder actuated tool, including a barrel for receivingin one end thereof a driveable fastener, a driving ram slideable withinthe barrel for driving the driveable fastener, and a chamber forreceiving an explosive cartridge in the end opposite the driveablefastener. Said barrel pivotally mounted to a handpiece whereby in afiring position the cartridge is nested within a breech block providedin the handpiece, and being pivotable away from said breech block forloading and unloading cartridges. Said barrel including a sleeve havinga finger adapted to engage and dislodge a cartridge from its chamber,and further including a dog adapted to engage the driving ram for movingthe driving ram rearwardly within the barrel. Said dog for moving thedriving ram and said finger for retracting the cartridge beingcooperative whereby the return of the driving ram creates air pressurebehind the cartridge at a point prior to full retraction of the drivingram, and at said point having the finger engaging (and thus dislodging)the cartridge whereby the continued retraction exerts a propelling forceto propel the cartridge out of the barrel end.

5 Claims, 5 Drawing Figures PATENTEBAPR I 61974 SHEET 1 OF 2 wivq w s Msw. a M NW %N 3 o F 1 ml. :1 0 w o o [MW NW. I [I d e 0 A l l g Q IN. a rk M...,..,..M.\ Wk 4. mm. Nu Sq w\w@ w mm wms New wk wx m N nU PATENTEDAPR 1 6 I914 3.804.315

SHEEI 2 OF 2 N N R POWDER ACTUATEI) TOOL HISTORY This invention relatesto a powder actuated tool wherein a driving ram is propelled by anexplosive force to drive a fastener into hard materials, e.g., concreteand the like.

Powder actuated tools such as contemplated by the present invention aredesigned for use in the construction industry for driving metal pins orstuds into hard surfaces such as concrete. The explosive force requiredfor such driving is generally contained in a cartridge that is insertedin a tight fitting chamber at the rear end of the barrel of the tool.When the tool is fired, the cartridge casing is expanded and becomesjammed in the chamber. The difficulty commonly experienced in attemptingto manually remove the cartridge is detrimental to the efficient andsafe use of the tool. Thus an object of the present invention is toprovide an improved cartridge ejection mechanism.

Very briefly, the present invention is believed most applicable to thetype of tool described and illustrated in the U.S. Pat. No. 3,494, I25issued to D. L. Robinson on Feb. l0, I970. The improvement is primarilyin the provision of a sleeve member that carries a finger for dislodgingthe cartridge and a return dog for returning the driving ram. The fingerand dog are so located with respect to each other and the relativepositions of the cartridge that the driving ram initially compresses airbehind the cartridge prior to full retraction of the ram so that as thefinger engages the cartridge and by the following completed retractionof the driving ram. the

. FIG. I showing the barrel ofthe tool pivoted away from the handpiece;1

FIG. 4 illustrates the spent cartridge being ejected from the tool; and

FIG. 5 is a partial view of the tool of FIG. I illustrating the meansfor disassembling a part of the tool.

Referring to FIGS. I thru 3 of the drawings, the tool illustrated iscomprised of two main portions which are referred to as the barrelassembly I0 and the handpiece I2. The handpiece includes theconventional components. A firing pin 14 is slideably mounted in thebreech block I6 but urged to the forward position relative to the breechblock 16 as shown in FIG. I by spring 18. The sear 20 carried by thefiring pin is urged downwardly as viewed in FIG. 1 by spring 22. Whenthe breech block 16 moves forward relative to the firing pin [4 as shownin FIG. 2 (as when the tool is removed from the work surface). the sear20 is urged by spring 22 past the shoulder 24 to lock the firing pin inthis rear position. Re-engaging the work surface forces the breech block16 and firing pin 14 rearwardly into position to be refired. Atrigger 26carries a trigger bar 28 which is adapted to engage the sear 20 andforce it off shoulder 24. Springs 30 and 32 urge return of the trigger26 and trigger bar 28.

THE BARREL ASSEMBLY A mounting ring 34 has an ear portion 36 that ispivotally connected by pin 38 to a barrel support section 40 ofhandpiece 12. A barrel 42 is held in the mounting ring by set screw 44which engages the slot 46 to permit limited movement of the barrel 42relative to the mounting ring 34. A barrel extension 48 is fixed in theend of the barrel 42 by screw threads 50 and set screw 52 insertedthrough a slot 54 in the end of the barrel extension. A guard 55 isfastened to the mounting ring 34 by a ring fastener 56. A driving ram 58has a front portion 58 of reduced diameter adapted to slide through theopening of the barrel extension 48, a rear portion 58" and anintermediate tappered portion 58". The tappered portion 58" is adaptedto mate with the entrance 60 of the opening in thebarrel extension 48. Ahead portion 62 of the driving ram, with sealing ring 64, effectivelyseals against passage of air therepast. The end of the barrel 42(oppositethe barrel extension) is provided with a cartridge receivingchamber 66, adapted to receive a cartridge 68.

As shown in FIG. I, with the barrel assembly 10 pivoted to its operableposition, and with the barrel moved rearwardly in mounting ring 34, thecartridge 68 is abutted against the breech block 16 and in line with thefiring pin 14. A sleeve 70 is mounted around the barrel 42 and includesa grip 72 to facilitate manual movement of the sleeve. A ring 74 on thesleeve is provided with a stop in the form of a set screw 76 projectedinto a slot 78 in the barrel 42. This set screw is adapted to engage afinger 80 which is free sliding in a slot 82 in the barrel 42. An upperboss 83 in the finger 80 is engaged by the stop 76 and forced rearward alimited distance relative to barrel 42. A st0p'8l on the barrel 42maintains the finger 80 in proper alignment and also prevents the fingerfrom sliding off the barrel 42. A downward flange 84 fits under thecartridge rim and dislodges the cartridge when said stop 76 abuts theboss 83 of finger 80. The ring 74 has a lug 86 to which a dog 88 ispivotally fastened by pin 90. A set screw 92 limits the pivotal movementof the dog 88. The dog 88 passes through a slot 9.4 in the barrel 42 andis located to engage a flange 96 of the driving ram 58.

OPERATION The operation of loading and unloading power load cartridgesis illustrated by the sequence of drawings 1 thru 4.

FIG. 1 illustrates the tool just after the cartridge 68 has been ignitedby firing pin 14 whereby the driving ram 58 has driven a fastener 98through a plate 100 and into a concrete support 102. It will be notedthat the rear end of the barrel 42 is securely nested in the breechblock 16 and the firing pin 14 is fully extended into the breech block16.

FIG. 2 illustrates the tool removed from its abutting engagement withthe plate 100 with the barrel 42 moved forward (manually orgravitationally) in mounting ring 34. The rear end of the barrel is thusfree of the breech block 16 and can be pivoted away from the handpiece12. In a conventional manner, the breech block 16 is biased forward andthe finger 14 is limited in its forward movement to reposition thefiring pin rearward of shoulder 24.

FIG. 3 illustrates the removal of the cartridge 68. With the barrelassembly pivoted away from the handpiece 12, the sleeve is pulled alongthe barrel. The dog 88 first engages the flange 96 of the driving ram 58which is thereby moved rearwardly relative to the barrel by manualpressure on grip 72. As the head 62 of the driving ram passes the end ofthe slot 94, it begins building pressure behind the spent cartridge 68.The cartridge being expanded is wedged in the chamber 66 and thus ratherthan being forced from the seating completes the seal and allows forpressure build up until the tip of set screw 76 engages finger 80 withdownward flange 84 mechanically dislodging the cartridge. At this pointa sufficient pressure is built up behind the cartridge which ismomentarily perpetuated by the continued movement of the driving ramtoward full retraction to blow the cartridge clear of the tool as shownin FIG. 4. The sleeve is then returned and a hook 104 on the sleevecatches the finger 80 and returns it to its initial position and a newcartridge is placed in the chamber. The barrel assembly is then pivotedback against the handpiece. Inadvertent pivoting of the barrel isprevented by a magnet 106 which acts to hold the barrel assembly in itsclosed position.

Several features are provided which make assembly and disassembly of thetool more convenient. Such disassembly is important for replacing and/orcleaning the driving ram 58. Thus the barrel extension 48 is screwedonto the end of the barrel 42 and locked against inadvertent removal byset screw 52 which is seated in a slot in the end of barrel extension48. Furthermore, set screw 52 cannot inadvertently be loosened becauseto do so would prevent the sleeve from being fully positioned onto thebarrel. The rearward end of the sleeve would project past the barrel andprevent the barrel assembly from being pivoted back into its operatingposition. Note also that the vibration from the tool being operated willnot cause loosening ofthe set screw 52 in that it is overlapped by ring74. The set screw 52 when seated in the slot in the end of the barrelextension also aligns the dog 88 in its slot 94 which extends into theend of the barrel extension.

It will be understood that the barrel extension 48 can be removed byfirst pivoting the barrel assembly 10 away from the handpiece l2,sliding the sleeve off the barrel. to expose the set screw 52, looseningthe set screw and simply unscrewing the barrel extension from thebarrel. The sleeve is moved to position the set screw 92 relative toopening 107 to permit insertion ofa tool. The set screw is unscrewed topermit the dog 88 to drop out of the barrel opening and the driving ramis then pushed through the front end of the barrel by a push rod 108 asillustrated in FIG. 5.

It will be understood that the above example is intended to illustrate apreferred embodiment of the invention, the full scope of which isestablished by the claims appended hereto.

What is claimed is:

l. A tool for explosively driving fasteners into hard surfacescomprising: a handpiece having a handle, a barrel supporting portionextending from the handle, a firing pin carried by the handle, andactivating means for activating movement ofthe firing pin along apredetermined path, a barrel assembly pivotally connected to the barrelsupporting portion, said barrel assembly including a barrel having oneend pivotable between positions into and out of the path of the firingpin, a rim type cartridge receiving chamber in said one end of thebarrel and a dislodging finger carried by the barrel forming a part ofsaid cartridge receiving chamber and being movable from a cartridgereceiving position to a reject position which movement mechanicallydislodges a cartridge in the chamber, a driving ram slideably carriedwithin the barrel between a forward position and a retracted positionadjacent the cartridge receiving chamber, a head portion on said drivingram having a substantially air tight fitting with a section of thebarrel adjacent the cartridge receiving chamber, and the improvementwhich comprises a slideable member slideable on the barrel, a firstmeans carried by the slideable member to move the driving ram rearwardlyto its retracted position in the barrel, and a second means cooperativewith the first means to engage the dislodging finger and therebymechanically dislodge a cartridge in the cartridge receiving chamberduring retraction of the driving ram.

2. A tool for explosively driving fasteners into hard surfacescomprising: a handpiece having a handle, a barrel supporting portionextending from the handle, a firing pin carried by the handle, andactivating means for activating movement of the firing pin along apredetermined path, a barrel assembly pivotally connected to the barrelsupporting portion of the handpiece, said barrel assembly including abarrel having one end pivotable between positions into and out of thepath of the firing pin, a rim type cartridge receiving chamber in saidone end of the barrel, a driving ram slideably carried within the barreland being moveable between a forward position in the barrel and aretracted position adjacent the cartridge receiving chamber, a headportion on said driving ram having a substantially air tight fittingwith the section of the barrel adjacent the cartridge receiving chamber,and the improvement which comprises a finger-like member provided on thesaid one end of the barrel having limited movement relative to thebarrel, said finger-like member having a flange forming a part of theentrance of the cartridge receiving chamber and positioned under the rimof a rim type cartridge seated within said chamber, a sleeve slideableon said barrel, said sleeve having a dog projected through a slot in thebarrel and adapted to engage the driving ram, said sleeve further havinga stop for engaging the finger-like member, said stop, finger-likemember, driving ram and dog being positioned relatively whereby movementof the sleeve rearward on the barrel first causes engagement of the dogon the driving ram to create an effective pressure against the cartridgeprior to the stop engaging the finger-like member and said stop engagingthe finger-like member to dislodge the cartridge at a postion where thedriving ram is spaced forward of its retracted position wherebycontinued retraction of the driving ram propels the dis lodged cartridgeout of the barrel.

3. A tool for explosively driving fasteners into hard surfaces asdefined in claim 2 wherein the finger-like member slides in a groove inthe barrel and including a hook provided at the end of the sleeve toengage and return the finger-like member upon return of the sleeve onthe barrel.

4. A tool for explosively driving fasteners into hard surfaces asdefined in claim 2 wherein said dog is pivotally connected to a lug ofthe sleeve, a set screw maintaining the lug projected through the slotand into engagement with the driving ram, said set screw being mountedin said mounting ring, a barrel extension threadably connected to thebarrel, and a set screw normally positioned under the sleeve for fixingthe position of the barrel extension on the barrel, said set screwprojecting into a slot in the barrel extension to orient the barrelextension relative to the barrel.

1. A tool for explosively driving fasteners into hard surfacescomprising: a handpiece having a handle, a barrel supporting portionextending from the handle, a firing pin carried by the handle, andactivating means for activating movement of the firing pin along apredetermined path, a barrel assembly pivotally connected to the barrelsupporting portion, said barrel assembly including a barrel having oneend pivotable between positions into and out of the path of the firingpin, a rim type cartridge receiving chamber in said one end of thebarrel and a dislodging finger carried by the barrel forming a part ofsaid cartridge receiving chamber and being movable from a carTridgereceiving position to a reject position which movement mechanicallydislodges a cartridge in the chamber, a driving ram slideably carriedwithin the barrel between a forward position and a retracted positionadjacent the cartridge receiving chamber, a head portion on said drivingram having a substantially air tight fitting with a section of thebarrel adjacent the cartridge receiving chamber, and the improvementwhich comprises a slideable member slideable on the barrel, a firstmeans carried by the slideable member to move the driving ram rearwardlyto its retracted position in the barrel, and a second means cooperativewith the first means to engage the dislodging finger and therebymechanically dislodge a cartridge in the cartridge receiving chamberduring retraction of the driving ram.
 2. A tool for explosively drivingfasteners into hard surfaces comprising: a handpiece having a handle, abarrel supporting portion extending from the handle, a firing pincarried by the handle, and activating means for activating movement ofthe firing pin along a predetermined path, a barrel assembly pivotallyconnected to the barrel supporting portion of the handpiece, said barrelassembly including a barrel having one end pivotable between positionsinto and out of the path of the firing pin, a rim type cartridgereceiving chamber in said one end of the barrel, a driving ram slideablycarried within the barrel and being moveable between a forward positionin the barrel and a retracted position adjacent the cartridge receivingchamber, a head portion on said driving ram having a substantially airtight fitting with the section of the barrel adjacent the cartridgereceiving chamber, and the improvement which comprises a finger-likemember provided on the said one end of the barrel having limitedmovement relative to the barrel, said finger-like member having a flangeforming a part of the entrance of the cartridge receiving chamber andpositioned under the rim of a rim type cartridge seated within saidchamber, a sleeve slideable on said barrel, said sleeve having a dogprojected through a slot in the barrel and adapted to engage the drivingram, said sleeve further having a stop for engaging the finger-likemember, said stop, finger-like member, driving ram and dog beingpositioned relatively whereby movement of the sleeve rearward on thebarrel first causes engagement of the dog on the driving ram to createan effective pressure against the cartridge prior to the stop engagingthe finger-like member and said stop engaging the finger-like member todislodge the cartridge at a postion where the driving ram is spacedforward of its retracted position whereby continued retraction of thedriving ram propels the dislodged cartridge out of the barrel.
 3. A toolfor explosively driving fasteners into hard surfaces as defined in claim2 wherein the finger-like member slides in a groove in the barrel andincluding a hook provided at the end of the sleeve to engage and returnthe finger-like member upon return of the sleeve on the barrel.
 4. Atool for explosively driving fasteners into hard surfaces as defined inclaim 2 wherein said dog is pivotally connected to a lug of the sleeve,a set screw maintaining the lug projected through the slot and intoengagement with the driving ram, said set screw being removeable topermit pivoting of the dog out of engagement with the driving ram toallow the driving ram to be ejected out of the barrel.
 5. A tool forexplosively driving fasteners into hard surfaces as defined in claim 3wherein the barrel assembly includes a mounting ring pivotally mountedto the barrel supporting portion, said barrel being slideably mounted insaid mounting ring, a barrel extension threadably connected to thebarrel, and a set screw normally positioned under the sleeve for fixingthe position of the barrel extension on the barrel, said set screwprojecting into a slot in the barrel extension to orient the barrelextension relative to the barrel.